#define _CRT_SECURE_NO_WARNINGS 1



#include<stdio.h>


int main()
{
	char arr[256] = { 0 };
	int i = 0, a = 0, b = 0;
	while (scanf("%c", &arr[i]) != EOF)
	{
		if (arr[i] == '@')
		{
			arr[i] = '\0';
			break;
		}
		if (arr[i] == '(')
			a++;
		else if (arr[i] == ')')
			b++;
		i++;
	}
	if (a != b)
		printf("NO\n");
	else
	{
		printf("YES\n");
	}

	return 0;
}